JDK14/Java14源码在线阅读
/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package jdk.nashorn.tools;
import jdk.nashorn.api.scripting.NashornException;
import jdk.nashorn.internal.codegen.Compiler;
import jdk.nashorn.internal.codegen.Compiler.CompilationPhases;
import jdk.nashorn.internal.ir.Expression;
import jdk.nashorn.internal.ir.FunctionNode;
import jdk.nashorn.internal.ir.debug.ASTWriter;
import jdk.nashorn.internal.ir.debug.PrintVisitor;
import jdk.nashorn.internal.objects.Global;
import jdk.nashorn.internal.objects.NativeSymbol;
import jdk.nashorn.internal.parser.Parser;
import jdk.nashorn.internal.runtime.Context;
import jdk.nashorn.internal.runtime.ErrorManager;
import jdk.nashorn.internal.runtime.JSType;
import jdk.nashorn.internal.runtime.Property;
import jdk.nashorn.internal.runtime.ScriptEnvironment;
import jdk.nashorn.internal.runtime.ScriptFunction;
import jdk.nashorn.internal.runtime.ScriptObject;
import jdk.nashorn.internal.runtime.ScriptRuntime;
import jdk.nashorn.internal.runtime.ScriptingFunctions;
import jdk.nashorn.internal.runtime.Symbol;
import jdk.nashorn.internal.runtime.arrays.ArrayLikeIterator;
import jdk.nashorn.internal.runtime.options.Options;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintStream;
import java.io.PrintWriter;
import java.io.StreamTokenizer;
import java.io.StringReader;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
import java.util.ResourceBundle;
import static jdk.nashorn.internal.runtime.Source.sourceFor;
/**
* Command line Shell for processing JavaScript files.
*/
public class Shell implements PartialParser {
/**
* Resource name for properties file
*/
private static final String MESSAGE_RESOURCE = "jdk.nashorn.tools.resources.Shell";
/**
* Shell message bundle.
*/
protected static final ResourceBundle bundle = ResourceBundle.getBundle(MESSAGE_RESOURCE, Locale.getDefault());
/**
* Exit code for command line tool - successful
*/
public static final int SUCCESS = 0;
/**
* Exit code for command line tool - error on command line
*/
public static final int COMMANDLINE_ERROR = 100;
/**
* Exit code for command line tool - error compiling script
*/
public static final int COMPILATION_ERROR = 101;
/**
* Exit code for command line tool - error during runtime
*/
public static final int RUNTIME_ERROR = 102;
/**
* Exit code for command line tool - i/o error
*/
public static final int IO_ERROR = 103;
/**
* Exit code for command line tool - internal error
*/
public static final int INTERNAL_ERROR = 104;
/**
* Constructor
*/
protected Shell() {
}
/**
* Main entry point with the default input, output and error streams.
*
* @param args The command line arguments
*/
public static void main(final String[] args) {
try {
final int exitCode = main(System.in, System.out, System.err, args);
if (exitCode != SUCCESS) {
System.exit(exitCode);
}
} catch (final IOException e) {
System.err.println(e); //bootstrapping, Context.err may not exist
System.exit(IO_ERROR);
}
}
/**
* Starting point for executing a {@code Shell}. Starts a shell with the
* given arguments and streams and lets it run until exit.
*
* @param in input stream for Shell
* @param out output stream for Shell
* @param err error stream for Shell
* @param args arguments to Shell
*
* @return exit code
*
* @throws IOException if there's a problem setting up the streams
*/
public static int main(final InputStream in, final OutputStream out, final OutputStream err, final String[] args) throws IOException {
return new Shell().run(in, out, err, args);
}
/**
* Run method logic.
*
* @param in input stream for Shell
* @param out output stream for Shell
* @param err error stream for Shell
* @param args arguments to Shell
*
* @return exit code
*
* @throws IOException if there's a problem setting up the streams
*/
protected final int run(final InputStream in, final OutputStream out, final OutputStream err, final String[] args) throws IOException {
final Context context = makeContext(in, out, err, args);
if (context == null) {
return COMMANDLINE_ERROR;
}
final Global global = context.createGlobal();
final ScriptEnvironment env = context.getEnv();
if (!env._no_deprecation_warning) {
System.err.println("Warning: The jjs tool is planned to be removed from a future JDK release");
}
final List<String> files = env.getFiles();
if (files.isEmpty()) {
return readEvalPrint(context, global);
}
if (env._compile_only) {
return compileScripts(context, global, files);
}
if (env._fx) {
return runFXScripts(context, global, files);
}
return runScripts(context, global, files);
}
/**
* Make a new Nashorn Context to compile and/or run JavaScript files.
*
* @param in input stream for Shell
* @param out output stream for Shell
* @param err error stream for Shell
* @param args arguments to Shell
*
* @return null if there are problems with option parsing.
*/
private static Context makeContext(final InputStream in, final OutputStream out, final OutputStream err, final String[] args) {
final PrintStream pout = out instanceof PrintStream ? (PrintStream) out : new PrintStream(out);
final PrintStream perr = err instanceof PrintStream ? (PrintStream) err : new PrintStream(err);
final PrintWriter wout = new PrintWriter(pout, true);
final PrintWriter werr = new PrintWriter(perr, true);
// Set up error handler.
final ErrorManager errors = new ErrorManager(werr);
// Set up options.
final Options options = new Options("nashorn", werr);
// parse options
if (args != null) {
try {
final String[] prepArgs = preprocessArgs(args);
options.process(prepArgs);
} catch (final IllegalArgumentException e) {
werr.println(bundle.getString("shell.usage"));
options.displayHelp(e);
return null;
}
}
// detect scripting mode by any source's first character being '#'
if (!options.getBoolean("scripting")) {
for (final String fileName : options.getFiles()) {
final File firstFile = new File(fileName);
if (firstFile.isFile()) {
try (final FileReader fr = new FileReader(firstFile)) {
final int firstChar = fr.read();
// starts with '#
if (firstChar == '#') {
options.set("scripting", true);
break;
}
} catch (final IOException e) {
// ignore this. File IO errors will be reported later anyway
}
}
}
}
return new Context(options, errors, wout, werr, Thread.currentThread().getContextClassLoader());
}
/**
* Preprocess the command line arguments passed in by the shell. This method checks, for the first non-option
* argument, whether the file denoted by it begins with a shebang line. If so, it is assumed that execution in
* shebang mode is intended. The consequence of this is that the identified script file will be treated as the
* <em>only</em> script file, and all subsequent arguments will be regarded as arguments to the script.
* <p>
* This method canonicalizes the command line arguments to the form {@code <options> <script> -- <arguments>} if a
* shebang script is identified. On platforms that pass shebang arguments as single strings, the shebang arguments
* will be broken down into single arguments; whitespace is used as separator.
* <p>
* Shebang mode is entered regardless of whether the script is actually run directly from the shell, or indirectly
* via the {@code jjs} executable. It is the user's / script author's responsibility to ensure that the arguments
* given on the shebang line do not lead to a malformed argument sequence. In particular, the shebang arguments
* should not contain any whitespace for purposes other than separating arguments, as the different platforms deal
* with whitespace in different and incompatible ways.
* <p>
* @implNote Example:<ul>
* <li>Shebang line in {@code script.js}: {@code #!/path/to/jjs --language=es6}</li>
* <li>Command line: {@code ./script.js arg2}</li>
* <li>{@code args} array passed to Nashorn: {@code --language=es6,./script.js,arg}</li>
* <li>Required canonicalized arguments array: {@code --language=es6,./script.js,--,arg2}</li>
* </ul>
*
* @param args the command line arguments as passed into Nashorn.
* @return the passed and possibly canonicalized argument list
*/
private static String[] preprocessArgs(final String[] args) {
if (args.length == 0) {
return args;
}
final List<String> processedArgs = new ArrayList<>();
processedArgs.addAll(Arrays.asList(args));
// Nashorn supports passing multiple shebang arguments. On platforms that pass anything following the
// shebang interpreter notice as one argument, the first element of the argument array needs to be special-cased
// as it might actually contain several arguments. Mac OS X splits shebang arguments, other platforms don't.
// This special handling is also only necessary if the first argument actually starts with an option.
if (args[0].startsWith("-") && !System.getProperty("os.name", "generic").startsWith("Mac OS X")) {
processedArgs.addAll(0, tokenizeString(processedArgs.remove(0)));
}
int shebangFilePos = -1; // -1 signifies "none found"
// identify a shebang file and its position in the arguments array (if any)
for (int i = 0; i < processedArgs.size(); ++i) {
final String a = processedArgs.get(i);
if (!a.startsWith("-")) {
final Path p = Paths.get(a);
String l = "";
try (final BufferedReader r = Files.newBufferedReader(p)) {
l = r.readLine();
} catch (final IOException ioe) {
// ignore
}
if (l != null && l.startsWith("#!")) {
shebangFilePos = i;
}
// We're only checking the first non-option argument. If it's not a shebang file, we're in normal
// execution mode.
break;
}
}
if (shebangFilePos != -1) {
// Insert the argument separator after the shebang script file.
processedArgs.add(shebangFilePos + 1, "--");
}
return processedArgs.stream().toArray(String[]::new);
}
public static List<String> tokenizeString(final String str) {
final StreamTokenizer tokenizer = new StreamTokenizer(new StringReader(str));
tokenizer.resetSyntax();
tokenizer.wordChars(0, 255);
tokenizer.whitespaceChars(0, ' ');
tokenizer.commentChar('#');
tokenizer.quoteChar('"');
tokenizer.quoteChar('\'');
final List<String> tokenList = new ArrayList<>();
final StringBuilder toAppend = new StringBuilder();
while (nextToken(tokenizer) != StreamTokenizer.TT_EOF) {
final String s = tokenizer.sval;
// The tokenizer understands about honoring quoted strings and recognizes
// them as one token that possibly contains multiple space-separated words.
// It does not recognize quoted spaces, though, and will split after the
// escaping \ character. This is handled here.
if (s.endsWith("\\")) {
// omit trailing \, append space instead
toAppend.append(s.substring(0, s.length() - 1)).append(' ');
} else {
tokenList.add(toAppend.append(s).toString());
toAppend.setLength(0);
}
}
if (toAppend.length() != 0) {
tokenList.add(toAppend.toString());
}
return tokenList;
}
private static int nextToken(final StreamTokenizer tokenizer) {
try {
return tokenizer.nextToken();
} catch (final IOException ioe) {
return StreamTokenizer.TT_EOF;
}
}
/**
* Compiles the given script files in the command line
* This is called only when using the --compile-only flag
*
* @param context the nashorn context
* @param global the global scope
* @param files the list of script files to compile
*
* @return error code
* @throws IOException when any script file read results in I/O error
*/
private static int compileScripts(final Context context, final Global global, final List<String> files) throws IOException {
final Global oldGlobal = Context.getGlobal();
final boolean globalChanged = (oldGlobal != global);
final ScriptEnvironment env = context.getEnv();
try {
if (globalChanged) {
Context.setGlobal(global);
}
final ErrorManager errors = context.getErrorManager();
// For each file on the command line.
for (final String fileName : files) {
final FunctionNode functionNode = new Parser(env, sourceFor(fileName, new File(fileName)), errors, env._strict, 0, context.getLogger(Parser.class)).parse();
if (errors.getNumberOfErrors() != 0) {
return COMPILATION_ERROR;
}
Compiler.forNoInstallerCompilation(
context,
functionNode.getSource(),
env._strict | functionNode.isStrict()).
compile(functionNode, CompilationPhases.COMPILE_ALL_NO_INSTALL);
if (env._print_ast) {
context.getErr().println(new ASTWriter(functionNode));
}
if (env._print_parse) {
context.getErr().println(new PrintVisitor(functionNode));
}
if (errors.getNumberOfErrors() != 0) {
return COMPILATION_ERROR;
}
}
} finally {
env.getOut().flush();
env.getErr().flush();
if (globalChanged) {
Context.setGlobal(oldGlobal);
}
}
return SUCCESS;
}
/**
* Runs the given JavaScript files in the command line
*
* @param context the nashorn context
* @param global the global scope
* @param files the list of script files to run
*
* @return error code
* @throws IOException when any script file read results in I/O error
*/
private int runScripts(final Context context, final Global global, final List<String> files) throws IOException {
final Global oldGlobal = Context.getGlobal();
final boolean globalChanged = (oldGlobal != global);
try {
if (globalChanged) {
Context.setGlobal(global);
}
final ErrorManager errors = context.getErrorManager();
// For each file on the command line.
for (final String fileName : files) {
if ("-".equals(fileName)) {
final int res = readEvalPrint(context, global);
if (res != SUCCESS) {
return res;
}
continue;
}
final File file = new File(fileName);
final ScriptFunction script = context.compileScript(sourceFor(fileName, file), global);
if (script == null || errors.getNumberOfErrors() != 0) {
if (context.getEnv()._parse_only && !errors.hasErrors()) {
continue; // No error, continue to consume all files in list
}
return COMPILATION_ERROR;
}
try {
apply(script, global);
} catch (final NashornException e) {
errors.error(e.toString());
if (context.getEnv()._dump_on_error) {
e.printStackTrace(context.getErr());
}
return RUNTIME_ERROR;
}
}
} finally {
context.getOut().flush();
context.getErr().flush();
if (globalChanged) {
Context.setGlobal(oldGlobal);
}
}
return SUCCESS;
}
/**
* Runs launches "fx:bootstrap.js" with the given JavaScript files provided
* as arguments.
*
* @param context the nashorn context
* @param global the global scope
* @param files the list of script files to provide
*
* @return error code
* @throws IOException when any script file read results in I/O error
*/
private static int runFXScripts(final Context context, final Global global, final List<String> files) throws IOException {
final Global oldGlobal = Context.getGlobal();
final boolean globalChanged = (oldGlobal != global);
try {
if (globalChanged) {
Context.setGlobal(global);
}
global.addOwnProperty("$GLOBAL", Property.NOT_ENUMERABLE, global);
global.addOwnProperty("$SCRIPTS", Property.NOT_ENUMERABLE, files);
context.load(global, "fx:bootstrap.js");
} catch (final NashornException e) {
context.getErrorManager().error(e.toString());
if (context.getEnv()._dump_on_error) {
e.printStackTrace(context.getErr());
}
return RUNTIME_ERROR;
} finally {
context.getOut().flush();
context.getErr().flush();
if (globalChanged) {
Context.setGlobal(oldGlobal);
}
}
return SUCCESS;
}
/**
* Hook to ScriptFunction "apply". A performance metering shell may
* introduce enter/exit timing here.
*
* @param target target function for apply
* @param self self reference for apply
*
* @return result of the function apply
*/
protected Object apply(final ScriptFunction target, final Object self) {
return ScriptRuntime.apply(target, self);
}
/**
* Parse potentially partial code and keep track of the start of last expression.
* This 'partial' parsing support is meant to be used for code-completion.
*
* @param context the nashorn context
* @param code code that is to be parsed
* @return the start index of the last expression parsed in the (incomplete) code.
*/
@Override
public final int getLastExpressionStart(final Context context, final String code) {
final int[] exprStart = { -1 };
final Parser p = new Parser(context.getEnv(), sourceFor("<partial_code>", code),new Context.ThrowErrorManager()) {
@Override
protected Expression expression() {
exprStart[0] = this.start;
return super.expression();
}
@Override
protected Expression assignmentExpression(final boolean noIn) {
exprStart[0] = this.start;
return super.assignmentExpression(noIn);
}
};
try {
p.parse();
} catch (final Exception ignored) {
// throw any parser exception, but we are partial parsing anyway
}
return exprStart[0];
}
/**
* read-eval-print loop for Nashorn shell.
*
* @param context the nashorn context
* @param global global scope object to use
* @return return code
*/
protected int readEvalPrint(final Context context, final Global global) {
final String prompt = bundle.getString("shell.prompt");
final BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
final PrintWriter err = context.getErr();
final Global oldGlobal = Context.getGlobal();
final boolean globalChanged = (oldGlobal != global);
final ScriptEnvironment env = context.getEnv();
try {
if (globalChanged) {
Context.setGlobal(global);
}
global.addShellBuiltins();
while (true) {
err.print(prompt);
err.flush();
String source = "";
try {
source = in.readLine();
} catch (final IOException ioe) {
err.println(ioe.toString());
}
if (source == null) {
break;
}
if (source.isEmpty()) {
continue;
}
try {
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